Subject
Petrology
Geology
14
Geology, Stratigraphic
12
Paleontology
5
Mines and mineral resources
3
Paleobotany
3
Borings
2
Coal
2
Edwards Aquifer (Tex.)
2
Fluorspar
2
Geochemistry
2
Mineralogy
2
Texas
2
Ascutney Mountain (Vt.)
1
Assaying
1
Chemistry, Inorganic
1
Corals, Fossil
1
Geology, Economic
1
Glacial epoch
1
Gold
1
Gryphaea
1
Mollusks, Fossil
1
Peridotite
1
Petroleum
1
Phosphates
1
Rivers
1
Rocks Analysis
1
Silicates
1
Silver ores
1
Turquoise
1
Uranium ores
1
Utah
1
Volcanic ash, tuff, etc
1
Volcanoes
1
Water-supply
1